Systems and methods for enhanced directionality in RFID portal systems

Abstract

Systems and methods for enhanced directionality for portal detector stations are provided. The systems include a portal detector station, an overhead detector station, a controller operatively coupled thereto. In embodiments, the controller analyzes read events detected by the portal detector station to determine a set of RFID tags included in a pallet of objects. The controller also analyzes read events detected by the overhead detector station to determine a direction of travel for the RFID tags included in the set of RFID tags and/or to detect stray read events that resulted in RFID tags being erroneously included in the set of RFID tags.

What is claimed: 
     
       1. A system for determining directionality of a radio frequency identification (RFID) tag within a venue, the system comprising:
 a first RFID transceiver arrangement configured to interrogate RFID tags disposed within a lane of a venue, wherein the first RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the lane; 
 a second RFID transceiver arrangement configured to interrogate RFID tags disposed within the venue, wherein the second RFID transceiver arrangement is configured to generate a beam in a plurality of directions relative to the second RFID transceiver arrangement, wherein at least one of the directions extends over at least a second portion of the lane, the second portion of the lane being proximate to the first portion of the lane; 
 a third RFID transceiver arrangement configured to interrogate RFID tags disposed within a second lane of the venue, wherein the third RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the second lane, wherein at least one of the directions for the beams generated by the second transceiver arrangement extends over at least a second portion of the second lane, the second portion of the second lane being proximate to the first portion of the second lane; and 
 a controller operatively connected to the first RFID transceiver arrangement the second RFID transceiver arrangement, and the third RFID transceiver arrangement, wherein the controller is configured to:
 detect, via the first RFID transceiver arrangement, a first plurality of read events respectively corresponding to a first set of RFID tags; 
 detect, via the second RFID transceiver arrangement, a second plurality of read events respectively corresponding to a second set of RFID tags, wherein the second plurality of read events occurred within a threshold time from the first plurality of read events; 
 determine that a particular RFID tag is included in both the first set of RFID tags and the second set of RFID tags; 
 based upon the read events for the particular RFID tag detected via the second RFID transceiver arrangement, determine a direction of travel for the particular RFID tag; and 
 associate the determined direction of travel with RFID tags included in the first set of RFID tags. 
 
 
     
     
       2. The system of  claim 1 , wherein:
 the first plurality of read events occurred within a read window; and 
 the second plurality of read events occurred within the threshold time before the read window or within the threshold time after the read window. 
 
     
     
       3. The system of  claim 2 , wherein to detect the first plurality of read events, the controller is configured to:
 determine a set of unique RFID tag identifiers corresponding to the read events that occurred within the read window. 
 
     
     
       4. The system of  claim 1 , wherein to determine the direction of travel for the particular RFID tag, the controller is configured to:
 determine a first position of the particular RFID tag based upon an angle of arrival of a first response received from the particular RFID tag at the second RFID transceiver arrangement; 
 determine a second position of the particular RFID tag based upon an angle of arrival of a second response received from the particular RFID tag at the second RFID transceiver arrangement; and 
 compare the first position to the second position to determine the direction of travel. 
 
     
     
       5. The system of  claim 4 , wherein to compare the first position to the second position, the controller is configured to:
 determine a shift in position along an axis defined by the lane of the venue. 
 
     
     
       6. The system of  claim 1 , wherein the controller is configured to:
 detect, via the third RFID transceiver arrangement, a third plurality of read events respectively corresponding to a third set of RFID tags; 
 detect, via the second RFID transceiver arrangement, a fourth plurality of read events respectively corresponding to a fourth set of RFID tags; 
 determine that a second RFID tag is included in both the third set of RFID tags and the fourth set of RFID tags, wherein the fourth plurality of read events occurred within a threshold time from the third plurality of read events; 
 based upon the read events for the second RFID tag detected via the second RFID transceiver arrangement, determine a direction of travel for the second RFID tag; and 
 associate the determined direction of travel with RFID tags included in the third set of RFID tags. 
 
     
     
       7. The system of  claim 6 , wherein the second set of read events overlaps the fourth set of read events. 
     
     
       8. The system of  claim 1 , wherein the controller is configured to:
 based upon the second plurality of read events, determine that a third RFID tag is not located in the second portion of the lane; and 
 delete the third RFID tag from the first set of RFID tags. 
 
     
     
       9. A system for detecting stray radio frequency identification (RFID) tag read events at a venue, the system comprising:
 a first RFID transceiver arrangement configured to interrogate RFID tags disposed within a lane of a venue, wherein the first RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the lane; 
 a second RFID transceiver arrangement configured to interrogate RFID tags disposed within the venue, wherein the second RFID transceiver arrangement is configured to generate a beam in a plurality of directions relative to the second RFID transceiver arrangement, wherein at least one of the directions extends over at least a second portion of the lane, the second portion of the lane being proximate to the first portion of the lane; 
 a third RFID transceiver arrangement configured to interrogate RFID tags disposed within a second lane of the venue, wherein the third RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the second lane, wherein at least one of the directions for the beams generated by the second transceiver arrangement extends over at least a second portion of the second lane, the second portion of the second lane being proximate to the first portion of the second lane; and 
 a controller operatively connected to the first RFID transceiver arrangement the second RFID transceiver arrangement, and the third RFID transceiver arrangement, wherein the controller is configured to:
 detect, via the first RFID transceiver arrangement, a first plurality of read events respectively corresponding to a first set of RFID tags; 
 detect, via the second RFID transceiver arrangement, a second plurality of read events respectively corresponding to a second set of RFID tags, wherein the second plurality of read events occurred within a threshold time from the first plurality of read events; 
 determine that a particular RFID tag is included in both the first set of RFID tags and the second set of RFID tags; 
 based upon the read events for the particular RFID tag detected via the second RFID transceiver arrangement, determine that the particular RFID tag is not located in the lane; and 
 delete the particular RFID tag from the first set of RFID tags. 
 
 
     
     
       10. The system of  claim 9 , wherein:
 the first plurality of read events occurred within a read window; and 
 the second plurality of read events occurred within the threshold time before the read window or within the threshold time after the read window. 
 
     
     
       11. The system of  claim 10 , wherein to detect the first plurality of read events, the controller is configured to: detect a plurality of read events that indicate a unique RFID tag identifier within the read window. 
     
     
       12. The system of  claim 9 , wherein to determine that the particular RFID tag is not located in the lane, the controller is configured to:
 determine a position of the particular RFID based upon an angle of arrival of a response received from the particular RFID tag at the second RFID transceiver arrangement; and compare the determined position to a geographic region corresponding to the lane. 
 
     
     
       13. The system of  claim 9 , wherein to determine that the particular RFID tag is not located in the second lane, the controller is configured to:
 determine that the particular RFID tag is not located in the second portion of the lane. 
 
     
     
       14. The system of  claim 9 , wherein the controller is configured to:
 detect, via the third RFID transceiver arrangement, a third plurality of read events respectively corresponding to a third set of RFID tags; 
 detect, via the second RFID transceiver arrangement, a fourth plurality of read events respectively corresponding to a fourth set of RFID tags; 
 determine that a second RFID tag is included in both the third set of RFID tags and the fourth set of RFID tags, wherein the fourth plurality of read events occurred within a threshold time from the third plurality of read events; 
 based upon the read events for the second RFID tag detected via the second RFID transceiver arrangement, determine that the particular RFID tag is not located in the second lane; and 
 delete the second RFID tag from the third set of RFID tags. 
 
     
     
       15. The system of  claim 14 , wherein the second set of read events overlaps the fourth set of read events. 
     
     
       16. The system of  claim 9 , wherein the controller is configured to:
 determine that a third RFID tag is included in both the first set of RFID tags and the second set of RFID tags; 
 based upon the read events for the third RFID tag detected via the second RFID transceiver arrangement, determine a direction of travel for the third RFID tag; and 
 associate the determined direction of travel with RFID tags included in the first set of RFID tags. 
 
     
     
       17. A method for determining directionality of a radio frequency identification (RFID) tag within a venue using an RFID tag tracking system, the RFID tag tracking system comprising (i) a first RFID transceiver arrangement configured to interrogate RFID tags disposed within a lane of a venue, wherein the first RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the lane; (ii) a second RFID transceiver arrangement configured to interrogate RFID tags disposed within the venue, wherein the second RFID transceiver arrangement is configured to generate a beam in a plurality of directions relative to the second RFID transceiver arrangement, wherein at least one of the directions extends over at least a second portion of the lane, the second portion of the lane being proximate to the first portion of the lane; (iii) a third RFID transceiver arrangement configured to interrogate RFID tags disposed within a second lane of the venue, wherein the third RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the second lane, wherein at least one of the directions for the beams generated by the second transceiver arrangement extends over at least a second portion of the second lane, the second portion of the second lane being proximate to the first portion of the second lane; and (iv) a controller operatively connected to the first RFID transceiver arrangement, the second RFID transceiver arrangement; and the third RFID transceiver arrangement, the method comprising:
 detecting, via the first RFID transceiver arrangement, a first plurality of read events respectively corresponding to a first set of RFID tags; 
 detecting, via the second RFID transceiver arrangement, a second plurality of read events respectively corresponding to a second set of RFID tags, wherein the second plurality of read events occurred within a threshold time from the first plurality of read events; 
 determining, by the controller, that a particular RFID tag is included in both the first set of RFID tags and the second set of RFID tags; 
 based upon the read events for the particular RFID tag detected via the second RFID transceiver arrangement, determining, by the controller, a direction of travel for the particular RFID tag; and 
 associating, by the controller, the determined direction of travel with RFID tags included in the first set of RFID tags. 
 
     
     
       18. A method for detecting stray radio frequency identification (RFID) tag read events at a venue using an RFID tag tracking system, the RFID tag tracking system comprising (i) a first RFID transceiver arrangement configured to interrogate RFID tags disposed within a lane of a venue, wherein the first RFID transceiver arrangement is configured to have a signal range that extends over at least a first portion of the lane; (ii) a second RFID transceiver arrangement configured to interrogate RFID tags disposed within the venue, wherein the second RFID transceiver arrangement is configured to generate a beam in a plurality of directions relative to the second RFID transceiver arrangement, wherein at least one of the directions extends over at least a second portion of the lane, the second portion of the lane being proximate to the first portion of the lane; and (iii) a controller operatively connected to the first RFID transceiver arrangement, the second RFID transceiver arrangement, the method comprising:
 detecting, via the first RFID transceiver arrangement, a first plurality of read events respectively corresponding to a first set of RFID tags; 
 detecting, via the second RFID transceiver arrangement, a second plurality of read events respectively corresponding to a second set of RFID tags, wherein the second plurality of read events occurred within a threshold time from the first plurality of read events; 
 determining, by the controller, that a particular RFID tag is included in both the first set of RFID tags and the second set of RFID tags; 
 based upon the read events for the particular RFID tag detected via the second RFID transceiver arrangement, determining, by the controller, that the particular RFID tag is not located in the second portion of the lane; and 
 deleting, by the controller, the particular RFID tag from the first set of RFID tags.